New AAOS Knee OA Guidelines Likely to Be Controversial

Janis C. Kelly

June 19, 2013

The newly revised American Academy of Orthopaedic Surgeons (AAOS) clinical practice guideline for knee osteoarthritis (OA) has already become a focus for controversy.

The most significant change from the 2008 clinical practice guideline is a strong recommendation against the use of intraarticular hyaluronic acid (HA viscosupplementation) for symptomatic knee OA. The revised guideline also recommends against the use of acupuncture, the use of glucosamine and chondroitin sulfate, and arthroscopy with lavage for primary knee OA. The guideline also reduced the maximum dosage for acetaminophen from 4000 to 3000 mg/day, with a note that it does not recommend for or against the use of acetaminophen, opioids, or pain patches because evidence of efficacy is inconclusive.

"Fourteen studies assessed intraarticular [HA] injections," said David S. Jevsevar, MD, MBA, chair of the AAOS Committee on Evidence-Based Quality and Value, which oversees the development of clinical practice guidelines. "Although a few individual studies found statistically significant treatment effects, when combined together in a meta-analysis, the evidence did not meet the minimum clinically important improvement thresholds."

Dr. Jevsevar, who is an orthopaedic surgeon, told Medscape Medical News that there might be a subgroup of responders who would be helped by intraarticular HA, but that subgroup has not been identified. "It was up to the manufacturers to identify the subgroup of responders, and they have not done that. Industry seems more concerned with fighting among themselves over market share than with proving that this approach works, even in a subgroup of patients. They have done studies comparing products but have not done studies showing that viscosupplementation actually works, even in a subgroup," he said.

Dr. Jevsevar noted that even with the publication bias reported by several systematic reviews on viscosupplementation, current published studies do not show a clinically effective response.

"Some peer reviewers were critical of this finding, especially in light of the important clinical practice implications," Dr. Jevsevar writes in an accompanying editorial. "Many highlighted prior systematic reviews supporting the use of HA. These reviews were analyzed and found to have several flaws. Most did not address the issues of publication bias, between-study heterogeneity, and clinical significance in determining final recommendations."

The AAOS guidelines recommend nonsteroidal anti-inflammatory drugs (NSAIDs) or tramadol for patients with symptomatic OA of the knee but was "unable to recommend for or against the use of acetaminophen, opioids, or pain patches" because of inconclusive evidence. (Of the 15 areas addressed by the AAOS work group, 7 were judged to have inconclusive evidence for or against the specific treatment considered.)

"I would not agree with the AAOS statements regarding acetaminophen," Roy Altman, MD, told Medscape Medical News. "The [American College of Radiology guidelines, which include acetaminophen,] remain unchanged and were reviewed in 2012. There is some question about the AAOS process in preparing these recommendations. My problem is that if guidelines continue to say that the literature does not support use of most medications, what are we going to treat our patients with? Placebos?"

"Based on my own experience, which includes a number of acetaminophen trials, you need at least 4 g/day to have any modest effect in osteoarthritis with acetaminophen used alone. The lower doses of 3 g/day are probably not effective if used alone. None of the published studies look at combination acetaminophen therapy, which is how the drug is used in actual practice. Acetaminophen in combination with tramadol is more effective than tramadol alone," said Dr. Altman, who is professor emeritus, Division of Rheumatology, University of California, Los Angeles.

Dr. Jevsevar responded, "If it is the case that in knee OA acetaminophen is more often used in combination than alone, then those studies need to be done, and they have not been. We evaluated acetaminophen as a sole treatment for knee OA. There was actually only 1 well-done study on that topic, and it showed that acetaminophen (4 g) did not work. The reason we left acetaminophen in the guideline at all is that it is inexpensive and may fill a gap. We don't think it is as effective as NSAIDs or as intraarticular corticosteroid injections, but for those patients recalcitrant to everything else, it may give a small benefit."

Other key recommendations in the guideline include: "Patients who only display symptoms of osteoarthritis and no other problems, such as loose bodies or meniscus tears, should not be treated with arthroscopic lavage. Patients with a Body Mass Index (or BMI) greater than 25 should lose a minimum of five percent of their body weight. Patients should begin or increase their participation in low-impact aerobic exercise."

Dr. Jevsevar and Dr. Altman both expressed concern that insurance companies and other third-party payers will use the AAOS guidelines to deny coverage.

"Even though we say in the guidelines that we don't want the guidelines used for coverage-based determinations, our fear is that payers will do that. All that clinical practice guidelines are meant to do is to provide you with the best information that exists today," Dr. Jevsevar said.

"It should be emphasized that virtually all guidelines say that the practice of medicine involves the individual patient and that for the practitioner, guidelines are suggestions. The problem is when third-party payers decide to use the guidelines to justify what are basically economic decisions. This can lead to time-consuming appeals from the physician and may require extensive costly documentation," Dr. Altman said.

Dr. Jevsevar concluded, "Evidence-based medicine is the doctor's judgment, the patient's values, and the evidence. No one of those trumps the others."

Dr. Jevsevar disclosed receiving financial support from Medacta USA and from Omni Life Sciences. Dr. Altman has disclosed no relevant financial relationships.

"Treatment of Osteoarthritis of the Knee." AAOS. Guidelines full text, Editorial full text


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